How do I replace the batteries in the SW-A2 sensor?

The batteries in the SW-A2 sensor shall last approximately 2 years with normal use, so battery replacement should not be necessary in the near future.  However, if you want to replace the batteries, make sure the reinstallation is taken care of securely to maintain the device’s waterproofing.  To replace the batteries, please follow the instructions below:

Step 1: Use a Phillips screwdriver to unfasten the four screws at the bottom of SW-A2.
Step 2: Open the top cover.
Step 3: Replace the two AAA batteries inside.
Step 4: Put the top cover back on.
Step 5: Use the Phillips screwdriver to fasten the four screws at the back of SW-A2.